HUMAN 72-KILODALTON TYPE-IV COLLAGENASE FORMS A COMPLEX WITH A TISSUE INHIBITOR OF METALLOPROTEASES DESIGNATED TIMP-2
HUMAN 72-KILODALTON TYPE-IV COLLAGENASE FORMS A COMPLEX WITH A TISSUE INHIBITOR OF METALLOPROTEASES DESIGNATED TIMP-2
复制标题
DOI：
10.1073/pnas.86.21.8207
复制
发表时间：
1989-11-01
影响因子：
11.1
通讯作者：
HE, CS
中科院分区：
文献类型：
--
作者：
GOLDBERG, GI;MARMER, BL;HE, CS
猿猴病毒 40 (SV40) 转化的人肺成纤维细胞分泌 72 kDa IV 型胶原酶和密切相关的 92 kDa IV 型胶原酶，而这种酶在亲本细胞系中未检测到。从这些细胞中纯化的 92 kDa IV 型原胶原酶与金属蛋白酶组织抑制剂 TIMP 形成非共价复合物。在此，我们报告从 HRAS 转化的人支气管上皮细胞、SV40 转化的肺成纤维细胞和正常皮肤成纤维细胞中纯化的 72 kDa IV 型原胶原酶与 24 kDa 抑制剂（此处称为“TIMP-2”）存在于稳定但非共价的化学计量复合物中。 TIMP-2 与 TIMP 密切相关，通过将该蛋白的部分氨基酸序列与 TIMP 的部分氨基酸序列进行比较证明，尽管 TIMP-2 不与 TIMP 特异性抗体发生交叉反应。 TIMP-2 抑制剂优先与 72 kDa IV 型胶原酶相互作用，而不是与 TIMP 专门形成复合物的 92 kDa IV 型胶原酶相互作用。 72-kDa IV 型胶原酶-TIMP-2 复合物可以用有机汞激活，产生具有催化能力的酶。激活与蛋白质氨基末端的自蛋白水解裂解同时发生，并且不需要复合物解离。通过进一步添加化学计量的纯化TIMP-2或重组TIMP，可以完全抑制复合物的活性和活化。
Simian virus 40 (SV40)-transformed human lung fibroblasts secrete both 72-kDa type IV collagenase and a closely related 92-kDa type IV collagenase that was not detected in the parental cell line. The 92-kDa type IV procollagenase purified from these cells exists in a noncovalent complex with the tissue inhibitor of metalloproteases, TIMP. Here we report that the 72-kDa type IV procollagenase purified from HRAS-transformed human bronchial epithelial cells, SV40-transformed lung fibroblasts, and normal skin fibroblasts exists in a stable but noncovalent stoichiometric complex with a 24-kDa inhibitor referred to here as "TIMP-2." TIMP-2 is closely related to TIMP, as demonstrated by comparison of the partial amino acid sequence of this protein to that of TIMP, although it does not cross-react with TIMP-specific antibody. The TIMP-2 inhibitor interacts with the 72-kDa type IV collagenase in preference to the 92-kDa type IV collagenase that forms a complex exclusively with TIMP. The 72-kDa type IV collagenase-TIMP-2 complex can be activated with organomercurials to yield a catalytically competent enzyme. Activation occurs concomitantly with autoproteolytic cleavage of the amino terminus of the protein and does not require dissociation of the complex. Both activity and activation of the complex can be completely inhibited by further addition of stoichiometric quantities of purified TIMP-2 or recombinant TIMP.